Devices and methods for controlling expandable prostheses during deployment

Abstract

Prosthesis delivery devices and methods are provided that enable precise control of prosthesis position during deployment. The catheter for delivering a prosthesis to a treatment site in a body lumen typically carries one or more self-expanding tubular prostheses within a sheath. A radially expandable control member is positionable within the prostheses and has an expanded shape which engages an inner surface of the prostheses to urge the prostheses outwardly against the sheath. The radially expandable control member therefore controls axial position of the prostheses during deployment. Thus one or more prostheses may be deployed at a treatment site precisely. When multiple prostheses are deployed, excessive spacing or overlap between adjacent prostheses is minimized. The prostheses of the present invention are often deployed in stenotic lesions in peripheral arteries as well as coronary arteries and other body lumens.

1. A catheter for delivering a prosthesis to a treatment site in a body lumen, the catheter comprising:
 a pusher tube having a proximal end and a distal end; 
 a sheath slidably disposed over the pusher tube; 
 one or more self-expanding tubular prostheses carried within the sheath which constrains the prostheses in a radially contracted configuration, the one or more prostheses being independently releasable from the sheath as the sheath is retracted relative to the pusher tube, the prostheses resiliently expanding upon release from the sheath; and 
 a radially expandable control member positionable within the prostheses and disposed over an elongate flexible member having a lumen therethrough that is adapted to receive a guidewire, the control member having an expanded shape which engages an inner surface of at least one of the prostheses to exert an outward force against the at least one prosthesis, the control member comprising a plurality of elongate struts having an arcuate configuration in the expanded shape, the control member being axially movable with the sheath and proximally movable relative to the elongate flexible member while in the expanded shape so as to slide relative to the prostheses in engagement therewith as the sheath is retracted relative to the pusher tube, 
 wherein the pusher tube is adapted to prevent proximal motion of the one or more self-expanding prostheses as the sheath is retracted. 
 
     
     
       2. The catheter of  claim 1  wherein the control member urges the prosthesis outwardly against the sheath. 
     
     
       3. The catheter of  claim 1 , wherein the control member urges the prosthesis outwardly against an interior surface of the sheath. 
     
     
       4. The catheter of  claim 1 , wherein the plurality of elongate struts are disposed distal to the pusher tube. 
     
     
       5. The catheter of  claim 1 , wherein the radially expandable control member expands with a distal-most prosthesis as the distal-most prosthesis expands. 
     
     
       6. The catheter of  claim 1 , wherein the expandable member is a metal. 
     
     
       7. The catheter of  claim 1 , wherein the plurality of elongate struts form a basket. 
     
     
       8. The catheter of  claim 7 , wherein at least some of the plurality of elongate struts are oriented axially and bend outwardly under compression. 
     
     
       9. The catheter of  claim 7 , wherein the plurality of elongate struts are metal. 
     
     
       10. The catheter of  claim 7 , wherein the plurality of elongate struts are a polymer. 
     
     
       11. The catheter of  claim 1 , wherein the expandable member is a polymer. 
     
     
       12. The catheter of  claim 1 , wherein the self-expanding tubular prostheses carry a therapeutic agent adapted to being released therefrom. 
     
     
       13. The catheter of  claim 12 , wherein the therapeutic agent comprises an anti-restenosis agent. 
     
     
       14. The catheter of  claim 1 , wherein the radially expandable control member engages at least two self-expanding prostheses simultaneously. 
     
     
       15. The catheter of  claim 1 , further comprising a handle near the proximal end of the pusher tube, the handle having a control mechanism adapted to actuate the sheath and the radially expandable control member during deployment of the self-expanding prostheses. 
     
     
       16. The catheter of  claim 15 , wherein the sheath is adapted to be retracted while the pusher tube remains fixed relative to the handle so as to expose at least one of the self-expanding tubular prostheses for deployment. 
     
     
       17. The catheter of  claim 1 , wherein the sheath has a radially expandable distal tip interactive with the control member disposed distally of the distal tip to enable a self-expanding prosthesis to be trapped therebetween to inhibit the prosthesis from jumping distally upon expansion. 
     
     
       18. The catheter of  claim 17 , wherein the distal tip is flared. 
     
     
       19. The catheter of  claim 17 , wherein the distal tip is expandable as the prosthesis expands. 
     
     
       20. The catheter of  claim 17 , wherein the distal tip has a plurality of tines arranged in a cylindrical pattern and extending distally from a distal end of the sheath. 
     
     
       21. The catheter of  claim 1 , wherein the one or more self-expanding prostheses comprise a plurality of self-expanding prostheses. 
     
     
       22. The catheter of  claim 21 , wherein the self-expanding tubular prostheses have a length in the range of about 2 mm to about 50 mm. 
     
     
       23. The catheter of  claim 21 , wherein each of the self-expanding prostheses have the same length. 
     
     
       24. The catheter of  claim 21 , wherein at least one of the self-expanding prostheses has a length different than at least another of the self-expanding prostheses. 
     
     
       25. The catheter of  claim 21 , wherein the self-expanding prostheses have ends in engagement with one another prior to deployment. 
     
     
       26. The catheter of  claim 21 , wherein the self-expanding prostheses are axially connected to each other when in the sheath. 
     
     
       27. The catheter of  claim 1 , wherein the pusher tube is proximal to the self-expanding prostheses. 
     
     
       28. The catheter of  claim 1 , wherein the pusher is adapted to engage a prosthesis in the sheath for retrieval thereof, thereby preventing the prosthesis from being deployed. 
     
     
       29. The catheter of  claim 1 , wherein the elongate flexible member is disposed at least partially under the pusher tube. 
     
     
       30. The catheter of  claim 29 , wherein the one or more prostheses comprise a plurality of self-expanding prostheses. 
     
     
       31. The catheter of  claim 30 , wherein the self-expanding tubular prostheses have a length in the range of about 2 mm to about 50 mm. 
     
     
       32. The catheter of  claim 30 , wherein each of the self-expanding prostheses have the same length. 
     
     
       33. The catheter of  claim 30 , wherein at least one of the self-expanding prostheses has a length different than at least another of the self-expanding prostheses. 
     
     
       34. The catheter of  claim 30 , wherein the self-expanding prostheses have ends in engagement with one another prior to deployment. 
     
     
       35. The catheter of  claim 30 , wherein the prostheses are axially connected when in the sheath. 
     
     
       36. A catheter for delivering a prosthesis to a treatment site in a body lumen, the catheter comprising:
 a pusher tube having a proximal end and a distal end; 
 a sheath slidably disposed over the pusher tube and having a distal tip; 
 one or more self-expanding tubular prostheses carried within the sheath which constrains the prostheses in a radially contracted configuration, the one or more prostheses being independently releasable from the sheath as the sheath is retracted relative to the pusher tube, the prosthesis resiliently expanding upon release from the sheath; and 
 a radially expandable control member positionable within the prostheses and disposed over an elongate flexible member having a lumen therethrough that is adapted to receive a guidewire, the control member having an expanded shape which engages an inner surface of at least one of the prostheses to exert an outward force against the at least one prosthesis so as to urge the prosthesis outwardly against the sheath, the control member comprising a plurality of elongate struts having an arcuate configuration in the expanded shape and the control member being axially movable with the sheath and proximally movable relative to the elongate flexible member while in the expanded shape so as to slide relative to the prosthesis in engagement therewith as the sheath is refracted relative to the pusher tube, 
 wherein the distal tip of the sheath is interactive with the control member to enable a prosthesis to be trapped therebetween to inhibit the prosthesis from jumping distally upon expansion, and 
 wherein the pusher tube is adapted to prevent proximal motion of the one or more self-expanding prostheses as the sheath is retracted. 
 
     
     
       37. The catheter of  claim 36 , wherein the distal tip is flared. 
     
     
       38. The catheter of  claim 36 , wherein the distal tip is expandable as the prostheses expand. 
     
     
       39. The catheter of  claim 36 , wherein the distal tip has a plurality of tines arranged in a cylindrical pattern and extending distally from a distal end of the sheath. 
     
     
       40. The catheter of  claim 36 , wherein the control member urges the prosthesis outwardly against an interior surface of the sheath. 
     
     
       41. The catheter of  claim 36 , wherein the plurality of elongate struts are disposed distal to the pusher tube. 
     
     
       42. The catheter of  claim 41 , wherein the struts are resilient and bend outwardly under compression. 
     
     
       43. The catheter of  claim 36 , wherein the expandable member is a metal. 
     
     
       44. The catheter of  claim 36 , wherein the plurality of elongate struts form a basket. 
     
     
       45. The catheter of  claim 44 , wherein at least some of the plurality of elongate struts are oriented axially and bend outwardly under compression. 
     
     
       46. The catheter of  claim 44 , wherein the plurality of elongate struts are metal. 
     
     
       47. The catheter of  claim 44 , wherein the plurality of elongate struts are a polymer. 
     
     
       48. The catheter of  claim 36 , wherein the expandable member is a polymer. 
     
     
       49. The catheter of  claim 36 , wherein the self-expanding tubular prostheses carry a therapeutic agent adapted to being released therefrom. 
     
     
       50. The catheter of  claim 49 , wherein the therapeutic agent comprises an anti-restenosis agent. 
     
     
       51. The catheter of  claim 36 , wherein the radially expandable control member engages at least two self-expanding prostheses simultaneously. 
     
     
       52. The catheter of  claim 36 , further comprising a handle near the proximal end of the pusher tube, the handle having a control mechanism adapted to actuate the sheath and the radially expandable control member during deployment of the self-expanding prostheses. 
     
     
       53. The catheter of  claim 52 , wherein the sheath is adapted to be retracted while the pusher tube remains fixed relative to the handle so as to expose at least one of the self-expanding tubular prostheses for deployment. 
     
     
       54. The catheter of  claim 36 , wherein the pusher tube is proximal to the self-expanding prostheses. 
     
     
       55. The catheter of  claim 54 , wherein the pusher is adapted to engage a prosthesis in the sheath for retrieval thereof, thereby preventing the prosthesis from being deployed. 
     
     
       56. The catheter of  claim 36 , further comprising an wherein the elongate flexible member is disposed at least partially under the pusher tube. 
     
     
       57. A method of delivering a prosthesis to a treatment site in a body lumen, the method comprising:
 positioning a delivery catheter at the treatment site, the delivery catheter having one or more self-expanding tubular prostheses thereon and covered by a sheath; 
 retracting the sheath so as to expose the prosthesis, the prosthesis resiliently expanding radially into contact with a wall of the body lumen; 
 radially expanding a control member slidably coupled to the delivery catheter; 
 engaging an interior surface of the prosthesis with the control member as the sheath is retracted, the control member being positioned distally of the sheath and retracted in conjunction with the sheath and exerting an outward force against the prosthesis to maintain the axial position of the prosthesis relative to the delivery catheter as the prosthesis is released from the sheath; and 
 releasing the self-expanding tubular prosthesis from the delivery catheter into the body lumen. 
 
     
     
       58. The method of  claim 57 , wherein the control member urges the prosthesis outwardly against the sheath. 
     
     
       59. The method of  claim 57 , wherein releasing the prosthesis comprises collapsing the radially expandable control member so that the radially expandable control member disengages from the inner surface of the prosthesis. 
     
     
       60. The method of  claim 57 , wherein the radially expandable control member comprises a plurality of elongate wire-like struts axially oriented and adapted to bend outwardly under compression. 
     
     
       61. The method of  claim 57 , wherein the delivery catheter carries a plurality of self-expanding tubular prostheses. 
     
     
       62. The method of  claim 61 , wherein the plurality of self-expanding tubular prostheses are releasably interconnected while disposed on the delivery catheter. 
     
     
       63. The method of  claim 62 , wherein the prostheses disconnect upon expansion. 
     
     
       64. The method of  claim 57 , further comprising retracting the control member axially in conjunction with the sheath so as to slide relative to the prosthesis in engagement therewith. 
     
     
       65. The method of  claim 57 , wherein at least some of the self-expanding tubular prostheses carry a therapeutic agent adapted to being released therefrom. 
     
     
       66. The method of  claim 65 , wherein the therapeutic agent comprises an anti-restenosis agent. 
     
     
       67. The method of  claim 57 , wherein at least another self-expanding prosthesis is retained in the sheath after the prosthesis is released. 
     
     
       68. The method of  claim 57 , wherein a distal end of the sheath radially expands as the self-expanding prostheses expand. 
     
     
       69. The method of  claim 68 , wherein the distal end of the sheath flares outwardly as the self-expanding prostheses expand. 
     
     
       70. The method of  claim 68 , wherein the distal end of the sheath is axially split into sections, the sections deflecting outwardly as the self-expanding prostheses expand. 
     
     
       71. The method of  claim 68 , wherein the distal end of the sheath resiliently returns to a non-expanded shape following release of the desired number of self-expanding prostheses. 
     
     
       72. The method of  claim 68 , wherein the distal end of the sheath resiliently returns to a non-expanded shape following retraction of the control member into the sheath. 
     
     
       73. The method of  claim 68 , wherein the distal end of the sheath is radially expanded by an outward force exerted by the control member. 
     
     
       74. The method of  claim 68 , wherein the distal end of the sheath is radially expanded by an outward force exerted by the self-expanding prostheses.